South West Bikers | Motorcycle Forum

My Honda CB-1 400 1989, is constantly overheating . Its worst in slow moving traffic where i'm stopping and starting, i've cheacked water and oil levels and there fine. what else could be causing this problem and any sloutions??

If the oil and water levels are ok and not contaminated (oil in water or vice versa) then check that the stat is opening as it should, and that the rad isn't clogged. Have the exhaust or fuelling been messed with, or the filter all clogged? if it's lean it will overheat.
Does your fan kick in as it should?

Well I took a look at it tonight. There wasn't nearly enough water in it. Plus it was running verry lean.

I don't believe the fan is working though. I shal get the test meter out on the weekend. Any tips on testing to see if it works or not?

Jonny wrote:Well I took a look at it tonight. There wasn't nearly enough water in it. Plus it was running verry lean.

I don't believe the fan is working though. I shal get the test meter out on the weekend. Any tips on testing to see if it works or not?

Pull the feed off "in" and "out" the temp sensor that runs to the fan and bridge them together. That will confuse the fan that the temp has reached the required temperture to need the fan to start.

If fan does not run then its eitheir fan or fuse or break between that is at fault.

Oh and have ignition on whilst testing this

Good idea thanks. I'll give that a go on the weekend.

If alls well with that i would recommend wiring a switch so you can manually turn it on during traffic

1. First do what Blimey has suggested.
2.If it doesn't actuate the fan, follow the wires back from the fan to the first connector block. Take a direct feed from the battery (or other suitable 12v power source) and connect to the fan wires and see if the fan go's then.

If 1. doesn't work but 2. does, the temperature sensor isn't working. If 2. doesn't work, the fan is dead